Party line identification system



NOV. 25, 1952 Q MYERS PARTY LINE IDENTIFICATION SYSTEM 2 SHEETS-SHEET 1Filed May 29, 1946 oov INVENTOR I y o. MYERS B (7 ATTORNQK Nov. 25, 19520. MYERS PARTY LINE IDENTIFICATION SYSTEM Filed May 29, 1946 2SHEETSSHEET 2 n wI M *5 mN\ mm Lll| INVENTOR 0; M VERS 2 A 7' TORNEVPatented Nov. 2 5, 1952 2,619,546 PARTY LINE IDENTIFICATION SYSTEM OscarMyers, Mount Vernon, N. Y., assignor to Bell Telephone Laboratories,Incorporated, New York, N. Y., a corporation of New York Application May29, 1946, Serial No. 672,949

23 Claims. 1

This invention relates to automatic telephone systems and moreparticularly to systems for identifying calling stations on party linesin such automatic telephone systems. 7

An object of the invention is to provide an improved method andarrangement for selectively controlling, over a subscribers line,registering devices at the central ofi'ice in accordance with anindividual characteristic of the calling device or dial at a callingsubscribers station.

A feature of the invention, which enables the foregoing object to beattained, resides in providing differently adjusted auxiliary means inassociation with the various dials on a party line, whereby operation ofa dial and its return to normal, in the transmission of one or more lineinterruptions representing a digit of the called number, causesapplication, at the dialing station, of signal potential to the lineduring transmission of the impulse interruptions of a different one ofthe digits of the called number as individually prescribed for thatstation by the adjustment of the auxiliary means thereat.

This feature may be altered slightly to enable the calling device at onestation to apply the signal potential to the line during two or moredigits of a called number to employ combinations of digits as theidentifying characteristic of that station on the party line. The otherparties would be enabled to usea different combination of digits.

A further feature resides in means at the central cflice responsive topulse interruptions of the line, and simultaneous application of saidsignal potential thereto, to selectively register said potentialapplication in accordance with the digital impulses during which it isapplied. This feature of course may be altered to provide means forselectively registering any combination of digits transmitted, each ofwhich combination is characterized as above by the simultaneoustransmission of the signal potential.

In this disclosure the former feature of the invention is characterizedin provision at each subscribers station on the party line of amechanism actuated by the operation of the dial prior to its release tonormal to selectively connect a source of solid ground potential to aswitch, by means of which switch the operation of the pulsing motormechanism of th dial, when the latter is released to normal, willconnect the ground potential to the line during the periods of lineinterruption which correspond to the open dial pulses transmitted bymeans of the pulsing motor mechanism as it simultaneously opens the line2 circuit in transmitting the impulses corresponding to a digit dialed.This mechanism is adjustable so that the application of this groundpotential is applied to the line during any desired series of impulses,the adjustment being preset to permit the application of the potentialduring the transmission of one predetermined digit of a called number orduring any combination of digital transmissions.

The secondly mentioned feature of the invention is characterized in thisdisclosure by modification of and addition to the existing relays orapparatus and wiring of an automatic telephone system, such as describedin Patent 2,093,117 to W. W. Carpenter, dated September 14, 1937, suchthat in addition to these apparatus and wiring being, responsive to theline interruptions corresponding to the dialing of a digit of a callednumber, as is their normal function, they will simultaneously therewithbe further responsive to the application, at the subscribers station tothe line terminating in this apparatus, of the aforementioned groundsignal potential applied during these interruption periods and toregister this potential in such a manner as to indicate to the centraloffice monitoring operator which digit or combination of digits dialedby the subscriber caused the application of the potential. Theregistering of this information, coupled with the aforementionedpredetermined setting of the mechanism at the subscribers station toapply the potential during the dialing of a given digit or given digitswill thus inform the operator at the central office with positiveindication as to which subscriber of the party line is making the call,each subscriber station on the line being arranged to apply the groundpotential during transmission of one different digit of a called numberor during a different combination of digits.

The indicator provided at the central office in this disclosure of theinvention is a series of lights, each operable by application of theabovementioned ground potential during a difierent dialed digit of acalled number. These lights may be modified as to circuit arrangement tobe energized by combinations of digits dialed as previously mentioned.

The foregoing general features of the invention, as well as others, willbe apparent from the following detailed description of the constructionand operation of the invention with drawings depicting one embodimentthereof, of which drawings the following is a general description:

Fig. 1 shows one feature of the present invention incorporated withexisting mechanism and circuits at a calling subscribers station. Thedotted portions of this drawing, except when obviously used to indicateomitted portions of new apparatus, indicate existing conditions, thesolid lines indicating mechanism and circuits added in accordance withthe present invention. An exploded view in perspective is used to moreclearly describe the invention.

Fig. 2 shows in schematic form another fea ture of the present inventionincorporated with existing circuits and apparatus in a cross bartelephone system such as described in Patent No. 2,093,117 to W. W.Carpenter, dated September 14, 1937. On this drawing, as in Fig. 1,dotted lines indicated existing apparatus and circuits, solid linesindicating newly added apparatus and circuits in accordance with thepresent invention.

Fig. 3 indicates part of a modification which may be made to theindicating lamp circuits of Fig. 2 to enable the lamps to be responsiveto any combination of two digits of a called number transmittedsimultaneously with the aforementioned signal potential.

The following is a detailed description of the construction andoperation of the invention described above in general terms.

In Fig. l familiar apparatus appears; namely, the handset resting inits'cradle 2, and thereby depressing a plunger 3, and a dial base 4carrying a dial 5 and a finger stop 6. Protruding from the bottom of thedial base 4 are two shafts 1 and 8 with shaft keys 9 and I5,respectively, integral thereto. shaft 1 is a continuation of the shaftupon which the dial 5 is fixed and thereby rotates with the dial 5 atthe same angular speed in both directions. Shaft S is a continuation ofthe shaft upon which the pulsing motor mechanism acts and the shaft 8therefore will make one complete rotation each time the dial 5 rotates adistance corresponding to the separation of two adjacent digit fingerholes upon release, after having been set to a given digit by rotationin the clockwise direction. The direction of rotation of the shaft 8 isclockwise only, under the action of the pulsing motor mechanism.

A cam II with keyway i2 is press-fitted to the shaft 8, the keyway |2accommodating in a snug fit the key H) of shaft 8. The ordinary normallyconnected pulsing contacts, l5 fixed and I6 movable, are augmented by athird fixed normally open contact H. The movable contact I6 isswitchable from contact with fixed contacts l5 and H alternately duringoperation of the pulsing motor mechanism through the cam II, andspecifically by virtue of the raised portion |3 of the cam Contact I5 isconnected to conductor 200 which is the ring conductor R for thesubscriber station. Contact I6 is connected to conductor 300 which inturn is in series with the existing hook switch |8 which in turnconnects to conductor 31H which becomes the tip conductor T of thesubscriber station. Contact I! is connected to conductor 400 which inturn is connected to a normally open movable contact IS, the action ofwhich is hereinafter described along with that of its cooperating fixedgrounded contact 20.

To the bar 2|, operated in a Well-known manner by plunger 3, avertically reciprocating bar 22 is attached by means of enlarged end 23thereof by any suitable means such as welding.- The bar 22 is slidablyguided in its vertically reciprocating motion by its slot 24 withinwhich fixed pin 25 rides as bar 22 is moved. The bar 22 is urged to itsfurthermost vertical position by sprin 26 attached to lug 2'! on bar 22and to a fixed lug 28. A surface 29 of the bottommost edge of bar 22,inclined in the longitudinal direction of bar 22 at the lower end ofsame, provides a stop surface for the curved end of a horizontallymovable bar 3| such that a change of vertical position of bar 22 willallow the bar 3| to assume a change of horizontal position. Bar 3| isslidably positioned in a horizontal direction by its slots 32 and 33within which respective fixed pins 3d and 35 ride as bar 3| is moved.Bar 3| is urged towards its furthermost horizontal position in thedirection of the vertical bar 22 by spring 36 attached to lug 31 on bar3| and to fixed lug 38. The end 39 of bar 3|, opposite to the curved end30 of same, is provided with an edge 40 which is cut back from the fullwidth of bar 3| by means of an inclined edge 4! to allow end 4| of ahold pawl 42 to rotate about the hold pawl fixed pivot 43, under theaction of spring 44, when the bar 3| is moved by spring 36 to itsfurthermost position towards the bar 22 when bar 22 is moved verticallyby spring 26 allowing the end 30 of bar 3| to change positionhorizontally by bearing on a different portion of the inclined edge-29of bar 22. Spring 54, attached to the hold pawl at hole 45 and to afixed lug 46, urges the pawl and end 4| thereof to rotatecounter-clockwise when permitted to do so by the aforementionednecessary position of bar 3| relative thereto as previously explained.When in the position shown in Fig. l, or its fur-'- thermost clockwiseposition, hold pawl 42 does not engage any teeth 59 of ratchet wheel 48.When in its counter-clockwise position it engages a tooth of ratchet 48.

A shaft 49 is rotatably held in fixed axial and translatory position byfixed plate 5| by means of being inserted into hole 50 in plate 5| untilthe shoulder 54 of the sleeve 55, rigidly attached to shaft 49, rests onplate 5| and a lock-ring 52 is attached to circumferential groove 53 ofshaft 49 on the opposite side of plate 5| from the aforementionedshoulder 54 of sleeve 55. Ratchet wheel 48 is rigidly attached to sleeve55 and urged in a clockwise direction by coil spring 56 attached theretoand to fixed pin 51. The ratchet wheel 48, in addition to having regularteeth engaged by hold pawl 42, has a stop tooth 58 which engages pin 59rigidly held by fixed plate 5|. This stop tooth 58 and stop pin 59determine the fully clockwise position of ratchet wheel 48 and sleeve 55and shaft 49 since the latter three are all mutually attached.

Attached to sleeve 55 is also a disc 5| having holes such as L32 and 63arranged near its periphery, into any one of which holes such as 63 aknob-ended pin dd is insertable. This knobended pin 5 is so arrangedthat it will, when rotated by disc 5| to the appropriate position,engage the insulated projection (5 attached to movable contact Hi andthereby move contact Hi to engagement with its cooperating fixedgrounded contact 26. There may be more than one knob-ended pin for eachdisc as will be explained later.

A second sleeve ti; on shaft 49 is separated from sleeve 55 at surface5? and is rotatable about shaft as as a shaft bearing and upon the upperend of sleeve 55 as a thrust bearing. Ratchet wheel 38 is rigidlyattached to sleeve 66 but not to shaft 69. Attached to ratchet wheel 68is a spring clutch it which extends over sleeve 55 but is not attachedthereto. The spring clutch 10 is arranged to slide over sleeve 55 whenratchet '5 wheel 68 is rotated clockwise and. to frictionally gripsleeve 55 and rotate same with it. when ratchet wheel 58is rotatedcounter-clockwise.

To shaft 1, connected to dial 5, a washer H, having a keyway 12, isattached such that the key 9 of shaft I will be accommodated by keyway72 of washer H such that the washer I! will rotate with shaft i. Machinescrew '59 is fastened to a suitably tapped hole in shaft 1 and in sodoing holds the pawl disc 15 and spring 78 in such a position that thepawl disc 15 will rotate about the shaft bearing surface Bil of screw 19and between the head of the screw '19 and the washer H as end bearings.Spring leis-attached to the disc pawl H5 at hole is therein and to thewasher H at hole 13. A pin it is rigidly attached to washer ll at M andengages a stop surface 8| on the operating tooth T5 of disc pawl 15. Thetooth of disc pawl 15 is arranged to engage teeth 69 of ratchet wheel68.

The operation of the mechanism of Fig. 1 previously described from aconstruction standpoint is as follows. When the handset I is lifted fromthe cradle 2, when a subscriber desires to initiate a call, the plunger3, bar 2| and consequently bar 22 are allowed to move vertically underthe action of spring 2'6, the hook switch It being closedsimultaneously. This movement will permit the end 39 of bar 31 to movehorizontally under the action of spring 36 to a new position abuttingagainst a new part of the inclined edge 29 of bar 22. When bar 3| moveshorizontally to the right, the end ll of hold pawl i2 will be rotatedcounter-clockwise under the action of spring 44 along the inclined edgell of bar 3i and will rest in the depression made by the cutback edge 49of the end 39 of bar 3|. In this rotation the hold pawl 52 will engageone of the normal teeth as of ratchet wheel 58. The ratchet wheel 53 isheld by means of its stop tooth 5 .3 against the stop 5!; on plate 5'!by the action of spring 55.

When the dial 5 is rotated clockwise'to finger stop 6, to dial the firstdigit of a called numher, the shaft i will rotate clockwise therewithand will carry washer ii with it. Washer it by means of pin it attachedthereto will engage the stop surface 8! on the operating tooth ll ofdisc pawl 15 and rotate the pawl 15 clockwise such as to enable thetooth T! to engage a tooth E9 of ratchet wheel 58 and rotate the latterone step. counter-clockwise. As the ratchet 58 and sleeve 65 and springclutch ill attached thereto rotate one step counter-clockwise the springclutch 15 will frictionally grip sleeve 55 and rotate same one stepcounter-clockwise. Shaft 35 and ratchet wheel 43 attached to sleeve 55will thereby be rotated one step counter-clockwise also. In thisrotation of ratchet $8 the hold pawl 52 will slide over a tooth onratchet 58 and engage the next succeeding tooth on the ratchet 48 tohold same in an advanced position of one step. in the rotation of sleeve55 the disc 6| attached thereto will be rotated one stepcounterclockwise also. The rotated step of disc 5| will be sufficient tomove a hole such as 62 into position of being adjacent the knob 65 oncontact 15. There is then no operation of contact l9 since the hole 52does not house the knob-ended pin 64 which actuates the contact [9 byengaging with the knob 65.

When the subscriber removes his finger from the finger hole of dial 5,allowing the disc to return to normal by rotating counter-clockwise, theshaft 1 is rotated counter-clockwise to its original position carryingwasher H with it. The spring 18 will force. the disc pawl 15, to followthe washer H and in so doing will. engage the tooth 69 of ratchet wheel68 in the reverse direction as previously and will rotate the wheel 63back to its original position. In rotating clockwise the ratchet wheel68 which is attached to sleeve 65 and spring clutch we will carry theselatter two with it. The spring clutch ll! when rotating clockwise willunwind from and frictionally dis.- engage the sleeve 55 andso will nottendto rotate same clockwise. So the sleeve 55 with the disc 6! remainas moved previously.

While the dial 5 is returning to itsnormal position in acounter-clockwise rotation the pulsing motor mechanism will rotate theshaft 8 and attached cam E3. The shaft Sand cam [3 will make onecomplete revolution each time the dial 5 revolves a distance equal tothe separation of adjacent finger holes of dial 5. It is seen that thecam E3 in rotating will break the normally closed contacts i5 and it andmake the normally open contacts i6 and I7. Thus a series of open pulsesis sent out along the TR circuit and the connection of contacts l8 and l1 does nothing since contacts l9 and 25 are open.

The operation described above is identical for the second digit and thedisc 51 is rotated one more step. The second hole, similar to 62, has noefiect on the knob 65. However, upon a succeeding operation of the dial5 corresponding to the dialing of a third digit the disc El will be seento be rotatable to a position where the knobended pin 64 will engage theknob 55 of contact l9 and close the connection of contacts I?) and 20and that operation of the cam l3 subsequent to release of the dial 5 onthis digit will not only send open dial pulses on the TR circuit butwill also send a series of solid ground pulses over the T line whencontacts l6 and ii are connected since contacts l9 and 20 are nowclosed.

The knob-ended pin 64 may be inserted in any hole 83 to correspond toany digit of the called number and so by this above-described mechanismit is possible tosend solid ground pulses over the T line during openpulses of any predetermined digit dialing of a called number and toprevent the sending of solid ground pulses over the T line during openpulses of any other digit at any one setting of the knob-ended pin 64.It is clear, of course, that more than one knob-ended pin such as 64 maybe employed with one disc 61 such that each station may transmit theground potential during any desired combination of digits of a callednumber, the combination different with each station on the party line.

When the handset l is replaced on the cradle 2 at any time plunger 3,bar 2| and bar 22 are depressed forcing bar 3| to the left and forcingthe hold pawl 42 to rotate clockwise by virtue of the end 4! thereofriding up the inclined edge 4! of theend 39 of bar 3! and releasing theratchet wheel 48. The spring 56 will rotate the ratchet wheel 48clockwise to its original position determined by stop tooth 58 ofratchet wheel 48 engaging stop pin 59 on plate 5|.

In Fig. 2 the apparatus and wiring shown in dotted lines are sorepresented as being apparatus and wiring existing in a telephone systemsuch as disclosed in Patent 2,093,117 to W. W. Carpenter, datedSeptember 14, 1937, previously referred to herein.

The tip and ring conductors T and R. of Fig. 1 from the subscriberstation, in passing through existing switching'apparatus 82, fullydescribed in the above patent, eventually terminate in an idle registersender on two normally open contacts 81 and 08, respectively, on thepresent cut-through relay 83 of said idle sender, designated as 2200 onFig. 22 of the reference patent. The contact 89 of relay 83 normally isconnected to the ground strap 9I; but, in order to employ the presentinvention this strap is removed and contact 89 is connected to anormally grounded armature 92 of a newly added so-called tip transferrelay 93. The existing contact 96 of relay 33 is normally connected tothe coil of relay 84, the present L relay associated with the idlesender and designated by 2291 on Fig. 22 of the reference patent, theother lead of the coil of relay 84 being normally connected to groundthrough a battery 94, as shown. The L relay 84 normally controls thecoil circuit of the present LI relay 85 associated with said idle senderdesignated by 2300 on Fig. 23 of the reference patent, and is unmodifiedin the use of the present invention. The grounded armature 95 of the Lrelay 84 is normally disconnected from the coil circuit of the LI relay05. When the L relay 04 is operated the grounded armature 95 thereofcloses a circuit from ground through the coil of the relay 85, throughbattery 99 to ground, operating relay 85. This armature 95 of the Lrelay 84 also completes the coil circuit of relay a present slow-release(SR) relay associated with the idle sender and designated as 22I I inFig. 22 of the reference patent, through battery 91 to ground.

The remaining elements of the apparatus already existing which are usedin the performance of this invention are the hold magnets A, B, C, TH,H, T and U, designated as such by respective numbers 202I, 2630, 2934,253?, 2051, 2650 and 2563 on Fig. 26 of the reference patent, these holdmagnets being also associated with said idle sender.

In short, the operations of these existing apparatus parts, are asfollows: At a given predetermined time, subsequent to closing of thehook switch at the subscriber station but before any dial pulses aretransmitted therefrom as explained in detail in the reference patent,the cutthrough relay 03 will operate and be so locked, thus closing thecoil circuit of the L relay 84 from the grounded armature 92 of the tiptransfer relay 93, through the now operated contact 90 and inner upperoperated armature 88 of the relay 83, around the tip ring circuit,through the now operated upper middle armature 8'! and operated contact89 of relay 83, through the coil of relay 84 to ground through thebattery 94. Relay 84 will operate energizing relay 95 by means ofcompleting its coil circuit through the now operated armature 95 andoperated contact 98 of relay 84. Relay 80 also will be energized by theoperated armature 95 and contact 90 of relay 84 completing the coilcircuit of SR. relay 86. The hold magnets A, B, C, TH, H, T and Uoperate successively after the completion of transmission of the seriesof dial pulses corresponding to digits successively transmitted by thesubscriber. The A magnet will operate at the conclusion of transmissionof the first digit pulses, B at the conclusion of the transmission ofthe second digit pulse, etc.

As the pulsing cam I3 of Fig. 1 transmits the open dial pulses of acalleddigit over the TR circuit, the cut-through relay 83 will remainlocked in the operated position, the L relay 84 will release and operatewith the'pulse interruptions thereby forcing the L1 relay to dolikewise. The SR. relay 86, however, due to its slow releasecharacteristic will remain operated over the short periods when its coilcircuit is deenergized by the release of the L relay 84 during the openpulses transmitted from the subscriber.

New armature I39 and contact I39 are added to the L1 relay 85 such thatnormally they are in mutual contact and become separated when Ll relay85 is operated. Armature I38 is connected to ground through a switchI31. Relay I00 is added with armature I50 and contacts I40, MI and I42.Armature I50 is normally not connected to contact I40 which is wired tothe contact I39 of the L1 relay 85. Also wired to the contact I39 of L1relay 85 is contact I4I of relay I00, contact I42 of relay I00 beingnormally connected to contact I 4| thereof. The coil circuit of relayI00 is connected from armature I50 on one side through battery I53 toground on the other side. The action of armature I50 and contact I42 ofrelay I00 is such that when the relay I00 is energized armature I50moves into contact with contact I40 and contact I42 separates fromcontact I4I. Contact I42 of relay I00 is wired to a newly added normallyunoperated armature I98 of the SR. relay 86. A second newly addedcontact 99 of the SR relay 86 connects to armature I98 thereof when theSR. relay 86 is operated.

A new tip transfer relay 93 is added, the coil circuit thereforextending to ground on one side through battery I43 and wired to contact99 of the SR relay 86 on the other side. The normally grounded armature92 of the tip transfer relay 93 has been mentioned previously. It isnormally separated from its cooperating contact I44 of the same relay. Asecond armature I52 of relay 93 is wired to ground and normallyseparated from its cooperating contact I5I of the same relay. ContactI5I of relay 93 is wired to the armature I50 of relay I00. Contact I44of relay 93 is wired to one side of the operating coil of newly addedground pulse detecting relay IOI, the opposite side of which coilcircuit extending to ground through battery I45. There is a hold coil onthe relay Ifil, one side of which connects to battery I45, the otherside being wired to a normally open contact I45 of relay I0 I Thecontact I45 is separated normally from its cooperating armature I41which is wired to ground through a switch I36. There is another contactI48 normally separated from armature I49 on relay IOI, the armature I49of which is wired to ground and the contact I48 of which is wired -to anewly added armature II! of the present hold magnet A. Two newly addedcontacts H9 and I20 on the present hold magnet A are arranged so thatnormally armature II'I connects to contact I20 and contact H9 isseparated from armature Ill. The operation of hold magnet A willseparate armatures II! and contact I20 thereof and connect armature II!and contact II9. Similar sets of an armature and contacts are added toeach of the hold magnets such as H3, I2I and I22 on hold magnet C. Thecontact I20 of hold magnet A is wired to one side of the 0011 of a newparty indicating relay I02, the other side of which coil is connected toground through battery I23. There are two contacts and two armatures onthe relay I02, all normally open. Armatures I2! and I28 are wiredtogether and to ground through a switch I33. Contact I25,

which is normally separated from but cooperating with armature I28, isconnected to previously mentioned contact I of hold magnet A. ContactI29, which is normally separated from but cooperating with armature I21,is wired to one side of a party indicating lamp I09 by wire 500, theother side of the lamp I09 being wired to ground through switch I andbattery H6. There is one party indicating relay I02, I03, I04, I05, I06,I01 and I08, respectively, for each hold magnet A, B, 0, TH, H, T and U.There is one party indicating lamp I09, IIO, III, H2, II3, H4 and H5 foreach respective party indicating relay and hold magnet such as partyindicating relay I04 for hold magnet C for party indicating lamp III.The party indicating relays are all wired identically except that eachone energizes a separate lamp, the lamps allbeing in parallel as to theswitch I35, battery It 6 and ground. The newly added normallydisconnected contacts of the hold magnets such as contact II9 of magnetA and contact I54 of magnet B are wired respectively to the newly addednormally unoperated armature of the next succeeding hold magnet such asarmature I55 of magnet B and armature I I8 of magnet C, respectively. Itis not deemed necessary to amplify this since the drawing of Fig. 2clearly shows the repetitive nature of this group of connections.

For the sake of describing the detailed operation of the inventioninitial reference is made to Fig. 1. In view of previous detaileddescriptions of the operation of the mechanism of Fig. 1 it issufficient for the sake of the understanding of the operation of Fig. 2to say that when the handset I is lifted preparatory to dialing thedigits of a called number, the TR loop is closed by the operation of theswitchhook I8 and by virtue of the initially closed contacts I5 and I6.Eventually, by reason of apparatus described in the referenced patent,relay 83 operates and is locked operated connecting the line to an idleregister sender. Contact 89 and armature 8'! of relay 83 meet andcontact 90 and armature 88 meet to complete the coil circuit of the Lrelay 84 through the TR loop to ground by way of armature 92 of relay93. When the L relay 84 operates, contact 98 and armature 95 thereonmeet completing to ground the coil circuits of the L1 relay 85 and theSR relay 86, each of which then operates. The L1 relay 85 in operatingopens connecting armature I38 and contact I39 thereon, switch I31 beingclosed. When the SR relay 86 operates, armature I98 and contact 99thereon are connected. Nothing further happens to the circuit of Fig. 1until the dial 5 of the subset is released from its operated position totransmit open dial pulses along the TR loop.

When the dial 5 is moved clockwise to stop 6 prior to release, theratched mechanism of Fig. 1 moves the disc 6| one step counter-clockwiseand looks it there. As shown in Fig. 1, this is the position which willmake the first hole in the disc 6| become adjacent the knob 65 ofcontact I9. Since the knob-ended pin 64 carried by disc 6| is in thethird hole 63, contacts I9 and 20 will not be connected.

Upon release of the dial 5 the cam I3 will open and close the contactsI5 and I6 a number of times corresponding to the digit dialed. Each timethe TR loop is opened in this manner, relay 83 being locked in theoperated position, the L relay 84 will release allowing the L1 relay 85to also release thus connecting armature I 38 and contact I39. The coilcircuit of the SR relay 86 will simultaneously be deenergized but therelay 86 will remain operated due to its slow release characteristicwhich is sufiicient to hold it operated during open pulses of a dialeddigit. Thus armature I96 and contact 99 thereon will remain connected.The coil circuit of the tip transfer relay 93 is now completed fromground through. battery I 43, the coil, closed contact 99 and armatureI98 of the SR relay 86, the closed contacts I42 and MI of relay I00 andthe closed contact I39 and armature I38 of the L1 relay to groundthrough switch I31. The relay 93 will be operated at this pointconnecting armature 92 and contact I44 thereon and contact I5I andarma-. ture I52 likewise. When contact I5I and armature I52 of relay 93are so connected, the coil cur-' rent circuit of relay I00 is completedfrom ground, through closed contact I5I and armature I52 of relay 93,through the coil of relay I00 to ground through battery I53. Relay I00will operate breaking the connection between its normally closedcontacts MI and I42 and connecting its normally separated contact I 40and armature I50. -It is seen that relay I00 by virtue of its contactI40 and armature I50, when closed, completes its own holding circuit byway of closed contact I39 and armature I38 of the L1 relay 85 to groundthrough switch I3'I.

Referring to Fig. 1 again it is noticed that as contacts I5 and I6 areseparated by the rotation of the cam I3, contacts I6 and I! areconnected. Thus, during each open pulse on the TR. line, the tipconductor 300 is connected to the movable contact I9 associated with theratchet and disc mechanism of Fig. 1. The knob-ended pin 64 on disc 6|,in the movement corresponding to the dialing of the first digit, has notengaged the knob 65 of contact I9. It is seen that this will not occuruntil the third digit is dialed since the knobended pin 64 is in thethird hole 63 of disc BI and is thus three ratchet steps from engagementwith the knob 65 of contact I 9.

When relay 93 operated, connecting armature 92 and contact I44 thereon,the ground pulse detectin relay IOI would have had a complete .coilcircuit if the tip conductor were grounded. Since the first step of theratchet of Fig. 1 did not connect contacts I9 and 20, the tip conductor,during interruptions in the TR loop caused by the cam I3, is notgrounded and relay IOI will not operate. Also, when the contacts I 4|and I42 of relay I00 are separated by the operation of this relay, thecoil circuit of relay 93 will be broken and relay 93 released allowingarmature 92 thereon to againground itself as normal. Contact I 5! andarmature I52 of relay 93 will also separate removing one ground from thecoil circuit of relay I00, which has established its own holdingcircuitby this time. However, as previously described the cam I3 will allowcontacts I5 and I6 to close subsequent to the first open pulse of thefirst dialed digit thus closing again momentarily the TR loop and againcomplete the coil circuit of the L relay 84. The L relay 84 operates,allowing the SR and L1 relay to be reenergized. The operation of the L1relay 85 will open the holding circuit of relay I00 which releases tonormal.

above steps for each open impulse of each digit;-

It is, however, important to note that upon dial- 11 ing-the thirddigit, the mechanism of Fig. 1 will have moved the disc 61 three stepscausing the knob-ended pin 64 to engage the knob 65 of movable'contactI9 and so move contact I9 into connection with the contact 20 which isgrounded. This will efiectively ground the tip conductor during openpulses since the cam I3 not only opens the'TR loop by separatingcontacts I5'and I6 but during'that period connects contacts I6 and I1.

It is also to be noted that at the completion of transmission of thefirst digit pulses the hold magnet A operated and locked and that at thecompletion of the transmission or the sec-- ond 'digit'pulses the holdmagnet B operated and locked.

'Retracing the description slightly, it will be remembered that duringopen pulses the armature 92 and contact I44 of relay 93 were connected.If the tip "conductor is grounded, the relay I'lH will have a completecoil circuit from this s ground, through its'coil, and through batteryI45 to "ground. Upon operating at this instant, relay I'DI closes itsown hold circuit by closing its'normally open contact I45 to armatureI41 to ground through switch I36. Also normally open contact I48 andarmature I49 of relay I-I will be closed. The coil circuit of partyindicating relay I04 will then be complete from ground, through closedcontact I48 and armature I49 of relay IOI, through operated armature II!and con-tact H9 of the operated and locked hold magnet A throughoperated armature I55 and contact 1540f the operated and locked holdmagnet B, through 'u'noperated aramture H8 and contact I22 ofunoperated-hold magnet Cand through the coil of relay I04'to'ground byway of battery I24. Upon operating, relay I04 closes its own holdcircuit by closing normally open contact I26 and armature I3I thereon toground through switch I34. Relay I04, in operating, also closes normallyopenarmature I30 and contact I 32 thereon, thus extending from groundthrough a switch I34 "a completed circuit for party indicating lamp IIIby wire I00 back to. ground through switch I 3 and'battery I I6. I

It is the result then that party indicating lamp III was lit by the subsriber station which contained the mechanism illustratedin Fig. .1 inwhich the important feature, as far as the foregoing description isconcerned, is that the knobended pin 64 was in the third hole '63 ofdisc BI. This fact, as has been shown, resulted in this particularsubset of the party lineproducing a lighted lamp III as a calle'dnumberwas dialed and specifically as the thirddigitof that number wastransmitted.

It is suflici'entto sayat this point that since the knob-ended pin 64can be preset to any given hole such as 63 of the disc 6I at the time ofinstallation, or subsequently for that matter, this invention willpermit positive party identification of each calling, party thereon,each partys subset mechanism being characterized by a different settingof the knob-ended pin 64 to efiect the lighting of a different lamp IIIcapable of being seen 'bya monitoring operator. It will be noted that,assuming the holding circuit of relay IE3! to be operative by means ofswitch Itfi being closed, once relay Isl has operated and lockedresponsive 'to a signal during a particular digit it will remainoperated until the switch use is opened. Under the assumed conditionstherefore lamps III, H2, H3, H4 and H5 will all light in :successionupon the operation in succession of -hold magnets C, TH, H and T.Nevertheless theoperationof the first lamp III will identify thecallingparty. However, the 'switch I35 may be left open entirely because thcombined operate timeof relay Iilii and release time of relay 93 will besufficient to enable the party identification relay "such as relay I 02to be operated by the operation of relay IBI. Furthermore, the switchI35 could represent contacts on any relay of the system which has anoperating cycle corresponding to the dialing of digits so that theholding circuit of relay it! would be opened at the end of each digitand closed upon the dialing of the next digit. Automatic systems alwaysinclude at least one such relay, as is well known in the art.

In regard to the monitoring last mentioned, .it is seen by anexamination of Fig. 2 and the abovedetailed description that referenceis made to switches I31 of the L1 relay B5, .iteof relay Iill, I33 ofrelay H32, I34 of relay lilii and I35 associated with lamps I69 throughH55. These switches .may be operable manually by the monitoring operatorseparately or simultaneously and may be so operable automatically bysuitable additional relays controlled by the calling subscribers setmechanism or controlled by the monitoring operator. The efiect ofoperating these switches is to release previously described relayholding circuits, to prevent operation of the circuits invented or.merely to prevent lighting of lights, .any one of which, or anycombination of which, may be desirable in the practice of the inventionbut which ar not considered important as to detailed description herein.It is also apparent that the lights I83 through II-ii used in thisdisclosureas the indicating means may be replaced .by any otherdesirable such means including circuit controlling means or meterswithout departing from the spirit of this invention.

In conclusion, by reference to Fig. it isclear that-new lamp. I55 isconnected, one side to conductor 5G0 and relay I122 the other side toconductor tilll and relay 1% through switch IE9, similar to I35 of Fig.2, and battery IE4. By means of thisslight modificationto the indicatinglampcircuits of Fig. 2 the party indicating lamp I56 will not beenergized until both relays I532 and'IiI3 havebeenoperated to completethe circuit for lamp I56 through grounds on both relays I 62 and W3. Inorder to energize or operate both relays I62 and I83, it is clear thatknobended pins such as he of Fig. 1 must have been in both the first andsecond holes of the disc 5|. By this arrangement the particular party,on the party line, which has this feature will cause lamp I55 to lightas the party dials the first two digits of a called number. It is, ofcourse, obviously possible by slight modification to the wiring of therelays I92 through Hi8 to enable the indicating lamps'to "be energizedonly by a combination of digits of 'more than two, this, of course,requiring more than two knobended pins to each party subset disc BI. Thelamps I51, I58 and I59 illustrated in Fig. 3 are shown to be energizedrespectively by the first and third digits, the second and fourth "andthe first and fourth, it not being considered necessary to illustratethe remaining seventeen possibili'ties of this two-digit codedarrangement. It is obvious that in order for the lamps to properlyregister only the combination of digits corresponding to the combinationof digits during which the signal was transmitted, the holding circuitfor relay IUI must be immobilized by, for

instance, opening switch I36 under such circumstances. Such is necessaryin order 'to prevent each lamp, after the first one lights, from beinglighted in succession to thereby prevent proper combinationidentification. With switch 1% opened during the identifying process, itwill be apparen-t'that the combined operate time of relay lcn andrelease time of relay et'must be sufficient to enable the operation ofthe pertinent party identification relay or relays H32 through I 58after the operation of relay lei, as previously explained. The holdingcircuit for relay llll could be eliminated entirely from the circuit ofFig. 2 but may, on the other hand, he desired to be retained for use inconnection with signal lamp identification. Also the holding circuit,switch I36 in particular, could be under the control of a relay whoseoperate and release cycle corresponds to the dialing of successivedigits, as previously explained.

The invention embodied in the foregoing description is not meant to belimited in scope thereto or to applications to the exemplarytelephonesystem referenced herein, but is limited only to the-scope ofthe appended claims.

What is 1 claimed is:

1-. Inan automatic telephone system including a-line circuit, aplurality of stations thereon, a central office terminating one end ofsaid line, and a calling device ateach station, a source of signalpotential at each station, means under the control of each of saidcalling devices for applying said signal potential to the line in apredetermined relation, differing with each station, to the sequence ofdigits of a called number simultaneously applied to the line by one ofsaid calling devices, and means at the central office selectivelyresponsive to the relation of digits of the called number to the signalpotential so applied to the line.

2. In an automatic telephone system including a central ofiice, a lineterminating therein, a plurality of stations on said line, and a callingdevice at each station, a source of signal potential at each station,means under the control of each station calling device for applying,said potential to the line simultaneously with at least one digit of acalled number transmitted by one of said calling devices, said one digitdiffering for each device, and means at the central oince adapted toselectively register the transmission of said potential with diiferentdigits of called numbers.

3. In an automatic telephone system including a line circuit, aplurality of stations thereon, a central office terminating one end ofsaid line, and a calling device at each station for transmitting groupsof line interruptions representing digits of a called number, a sourceof signal potential at each station, means under the control of each ofsaid'calling devices for connecting the signal potential to the lineduring the interruption intervals of at least one digit of the callednumber, said one digit different for each device, and means at thecentral ofiice responsive during at least one of said groups of lineinterruptions to the simultaneous connection of said potential source tothe line to selectively register the connecticn'ol' said source to saidline in accordance with its occurrence in the series of digitstransmitted.

4. In an automatic telephonesystem including a central office, a lineterminatingtherein, a plurality of stations on said line, and a dial ateach station adapted to interrupt the line .at leaston'cezinrresponseitoseach operation andmetum to 14 normal of the dial totransmit the impulses of a digit of a called number, a source of signalpotential at each station, means under the control of each station dialfor applying said potential to the line during the line interruptionsrepresenting at least one digit, different with each station, and meansat the central office responsive to interruptions of the line andsimultaneous application thereto of said signal potential to selectivelyregister the application to the line of said signal potential inaccordance with the digital line interruptions during which the saidpotential was so applied.

5. In an automatic telephone system including a central ofiice, a lineterminating therein, and a plurality of stations on said line, eachstation having a dialand a source of signal potential thereat, a stationidentification system comprising means under th control of the dial ofeach station for applying said potential to the line simultaneously withat least one digit of a dialed number, a difierent digit with eachstation, and means at the central office selectively responsive to thesimultaneous application to the line of'the potential and at least onedigit, whereby a register at the central omce is operated to indicatethe station dialing a called number.

6. In an automatic telephone system including a central office, a lineterminating therein, and a plurality of stations on said line, eachstation having a dial and a source of signal potential thereat, astation identification system comprising means under the control of thedial of each station for applying said signal potential to the linduring the line interruptions representing at least one digit of acalled number, a difi'erent digit with each station, and means at thecentral office selectively responsive to the application of thepotential to the line during the line interruptions, whereby a registerat the central o'ffice is operated to indicate th station dialing acalled number.

7. In an automatic telephone system including a line circuit, aplurality of stations thereon, a central oflice terminating one end ofsaid line, and a calling device at each station adapted to be operatedrepeatedly from normal to a plurality of positions and:to restore tonormal, during each of which restorations the line circuit ismomentarily interrupted at least once, depending on the position towhich said device is operated, to thereby transmit pulses representing adigit of a called number, a source of signal potential at each station,means under the control of each of said calling devices for makingeffective the signal potential'upon the operation of one of said devicescorresponding to at least one given digit, different with each station,and for applying said effective potential to the line during theinterruptions to same when said one device subsequently restores, andmeans at the central office responsive during said line interruptions tothe simultaneous application of said eiiective potential to the line toselectively register said application in accordance with its occurrencein the series of digits of the called number transmitted by repeatedoperation and restoration to normal of said one device.

8. In an automatic telephone system including a central office, a lineterminating therein, and a. plurality of stations on said line, eachstation having a dial and a source of signal potential thereat, saiddial adapted .to be operated repeatedlyfrom normal to a plurality ofpositions and to restore to normal, during each of which restorationsthe line circuit is momentarily interrupted at least once, depending onthe position to which said dial is operated, to thereby transmit pulsesrepresenting a digit of a called number, a station identification systemcomprising means under the control of each of said calling dials formaking effective the signal potential upon the operation of one of saiddials corresponding to at least one given digit, difierent with eachstation, and for applying said efiective potential to the line duringthe interruptions to same when said one dial subsequently restores, andmeans at the central oflice responsive during said line interruptions tothe simultaneous application of said efiective potential to the line toselectively register said application in accordance with its occurrencein the series of digits of the called number transmitted by repeatedoperation and restoration to normal of said one dial.

9. In an automatic telephone system including a central ofiice, a lineterminating therein, a plurality of stations on said line, and a callingdevice at each station, a source of signal potential at each station,means under the control of each station calling device for applying saidpotential to the line simultaneously 'with each digit of a combinationof digits of a called number transmitted by one of said calling devices,said combination of digits differing for each station, and means at thecentral oflice adapted to selectively register the transmission of saidpotential with diiferent combinations of digits of called numbers.

1-0. In an automatic telephone system including a line circuit, aplurality of stations thereon, a central oflice terminating one end ofsaid line, and a calling device at each station for transmitting groupsof line interruptions representing digits of a called number, a sourceof signal potential of each station, means under the control of each ofsaid calling devices for connecting the signal potential to the lineduring each group of the interruption intervals of a combination ofdigits of the called number, said combination of digits differing foreach station, and means at the central ofiice responsive during each ofsaid groups of line interruptions comprising said combination of digitsto the simultaneous connection of said potential source to the line toselectively register the connection of said source tosaid line inaccordance with its occurrence in the combination of digits sotransmitted.

11. In an automatic telephone system including a central oflice, a lineterminating therein, a plurality of stations on said line, and a dial ateach station adapted to interrupt the line at least once in response toeach operation and return to normal of the dial to transmit the impulsesof a digit of a called number, a source of signal potential at eachstation, means under the control of each station dial for applying saidpotential to the line during the line interruptions representing each ofa combination of digits, a different combination with each station, andmeans at the central ofiice responsive to interruptions of the line andsimultaneous application thereto of said signal potential to selectivelyregister the application to the line of said signal potential inaccordance with the combination of digits, during the line interruptionsof which the said potential was so applied.

12. In an automatic telephone system including a central office, a lineterminating therein, and a plurality of stations on said line, eachstation having a dial and a source ofsignal potential thereat, a stationidentification system comprising means under the control of the dial ofeach station for applying said potential to the line simultaneously witheach of a combination of digits of a dialed number, a differentcombination with each station, and means at the central oiflceselectively responsive to the simultaneous application to the line ofthe potential and each of the digits of the combination, whereby aregister at the central ofiice is operated to indicate the stationdialing a called number. I

13. In an automatic telephone system including a central office, a lineterminating therein, and a plurality of stations on said line, eachstation having a dial and a source of signal poten-' tial thereat, astation identification system comprising means under the control of thedial ofeach station for applying said signal potential to the lineduring the line interruptions representing each of a combination ofdigits of a called number, a different combination with each station,and means at the central oifice selectively responsive to theapplication of the potential to the line during the line interruptionsrepresenting each of the digits of the combination, whereby a registerat the central ofiice is operated to indicate the station dialing acalled number.

14. In an automatic telephone system including a line circuit, aplurality of stations thereon, a central omce terminating one end ofsaid line,- and a calling device at each station adapted to be operatedrepeatedly from normal to a plurality of positions and to restore tonormal, during each of which restorations the line circuit ismomentarily interrupted at least once, depending on the position towhich said device is operated, to thereby transmit pulses representing adigit of a called number, a source of signal potential at each station,means under the control of each of said calling devices for makingeffective the signal potential upon the operation of one of said devicescorresponding to each of a given combination of digits, a difierentcombination with each station, and for applying said effective potentialto the line during the interruptions to same when said one devicesubsequently restores, and means at the central oflice responsive duringsaid line interruptions to the simultaneous application of saideiTective potential to the line to selectively register said applicationin accordance with its occurrence in the given combination of digits ofthe called number transmitted by repeated operation and restoration tonormal of said one device.

15. In an automatic telephone system includ-' ing a central office, aline terminating therein, and a plurality of stations on said line, eachstation having a dial and a source of signal potential thereat, saiddial adapted to be operated repeatedly from normal to a plurality ofpositions and to restore to normal, during each of which restorationsthe line circuit is momentarily interrupted at least once, depending onthe position to which said dial is operated, to thereby transmit pulsesrepresenting a digit of a called number, a station identification systemcomprising means under the control of each of said calling dials formaking effective the signal potential upon the operation of one of saiddials corresponding to each of a given combination of digits, adifferent combination with each station, and for applying said effectivepotential to the line during the interruptions to same when said onedial subsequently restores, and means at the central oince responsiveduring said line interruptions to the simultaneous application of saideffective potential to the line to selectively register said applicationin accordance with its occurrence in the given combination of digits ofthe called number transmitted by repeated operation and restoration tonormal of said one dial.

16. In an automatic telephone system including a line circuit, aplurality of stations thereon, a central ofiice terminating one end ofsaid line, and a calling device at each station adapted to be operatedrepeatedly from normal to a plurality of positions and to restore tonormal, during each of which restorations the line circuit ismomentarily interrupted at least once, depending on the position towhich said device is operated, to thereby transmit pulses representing adigit of a called number, a source of ground signal potential at eachstation, means under the control of each of said calling devices formaking effective the ground potential upon the operation of one of saiddevices corresponding to each of two given digits, 2. different pair ofdigits for each station, and for applying said effective ground to theline during the interruptions to same when said one device subsequentlyrestores, and means at the central ofiice responsive during said lineinterruptions to the simultaneous application of said eifective groundto the line to selectively register said application in accordance withits occurrence in the given pair of digits of the called numbertransmitted by repeated operation and restoration to normal of said onedevice.

17. In an automatic telephone system including a central oifice, a lineterminating therei n, and a plurality of stations on said line, eachstation having a dial and a source of ground signa1 potential thereat,said dial adapted to be operated repeatedly from normal to a pluralityof positions and to restore to normal, during each of which restorationsthe line circuit is momentarily interrupted at least once, depending onthe position to which said dial is operated, to thereby transmit pulsesrepresenting a digit of a called number, a station identification systemcomprising means under the control of each of said calling dials formaking efiective the ground potential upon the operation of one of saiddials corresponding to each of two given digits, a different pair ofdigits for each station, and for applying said effective ground to theline during the interruptions to same when said one dial subsequentlyrestores, and means at the central ofiice responl sive during said lineinterruptions to the simultaneous application of said effective groundto the line to selectively register said applications in accordance withits occurrence in the pair of given digits of the called numbertransmitted by repeated operation and restoration to normal of said onedial.

18. The structure of claim '7 wherein said means for making effectivethe signal potential and for applying said efiective potential to theline includes first means under the control of each of said callingdevices for making efiective the signal potential upon the operation ofone of said devices corresponding to at least one given digit, difierentwith each station, and second means under the control of each of saidcalling devices for applying said effective potential to the line duringthe interruption to same when said one device subsequently restores.

19. The structure of claim 25 wherein said means for making effectivethe signal potential and for applying said effective potential to theline includes first means under the control of each of said callingdials for making effective the signal potential upon the operation ofone of said dials corresponding to at least one given digit, diiferentwith each station, and second means under the control of each of saidcalling dials for applying said effective potential to the line duringthe interruption to same when said one dial subsequently restores.

20. The structure of claim 14 wherein saidmeans for making effective thesignal potential and for applying said effective potential to the lineincludes first means under the control of each of said calling devicesfor making effective the signal potential upon the operation of one ofsaid devices corresponding to each of a given combination of digits, adifferent combination with each station, and second means under thecontrol of each of said calling devices for applying said effectivepotential to the line during the interruption to same when said onedevice subsequently restores.

21. The structure of claim 15 wherein said means for making eifectivethe signal potential and for applying said effective potential to theline includes first means under the control of each of said callingdials for making effective the signal potential upon the operation ofone of said dials corresponding to each of a given combination ofdigits, a different combination with each station, and second meansunder the control of each of said calling dials for applying saideifective potential to the line during the interruption to same whensaid one dial subsequently restores.

22. The structure of claim 16 wherein said means for making effectivethe ground potential and for applying said effective ground to the lineincludes first means under the control of each of said. calling devicesfor making effective the ground potential upon the operation of one ofsaid devices correspondingto each of two given digits, a different pairof digits for each station, and second means under the control of eachof said calling devices for applying said effective ground to the lineduring the interruption to same when said one device subsequentlyrestores,

23. The structure of claim 17 wherein said means for making effectivethe ground potential and for applying said effective ground to the lineincludes first means under the control of each of said calling dials formaking effective the ground potential upon the operation of one of saiddials corresponding to each of two given digits, a different pair ofdigits for each station, and second means under the control of each ofsaid calling dials for applying said effective ground to the line duringthe interruption to same when said one dial subsequently restores.

o-soma MYERS.

REFERENCES CITED The following references are of record in the file ofthis patent:

.UNITED STATES PATENTS Number Name Date 2,013,171 Peterson Sept. 3, 19352,410,520 Ostline Nov. 5, 1946

